Want to get a SSD

Most games get ZERO benefit from being on a SSD - the only ones that are good to put on there are MMOs and single player games that have a LOT of long loading screens.

Get a 128GB SSD and a 1TB hard drive. The 840pro is great, as is the OCZ Vector, but there's not really any need to spend that much - an 830 or Vertex 4 are both extremely good, reliable drives.
 
Agreed with the 128 and larger HDD, however if you use steam or other programs for large detailed single player games you can rotate installations onto a smaller SSD with relative ease. In games like skyrim and others of its ilk you can save a lot of time with loading screen time cut in half it seems. So if you can afford it get a 256GB, just make sure you have plenty of HDD storage as well.